# SergioV

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## Posts posted by SergioV

1. ### Variable temperature in a BEAM

On 3/6/2020 at 10:30 PM, Simon Križnik said:

Yes, according to Learn Thermal Analysis with Altair OptiStruct ebook:

Attached is an example from the ebook which I modified to include multiple heat sources (ambient & local).

Note: The ambient temperature is applied with convection on the outer surface. The local temperature is imposed at one end of the tube. This approach is valid for 3D elements, but not for 1D beams.

And is there any way of doing it with 1D beams?

2. ### Variable temperature in a BEAM

And is there any way of doing it with 1D beams?

3. ### Multiple Loads/pressures/gravity in hypermesh

On 1/30/2018 at 6:54 AM, Sanjay Nainani said:

Hello,

S1 is the scale factor.

Then i think you can do a linear static analysis. In that reference the constraint and in place of "Load" reference the "LOADADD" load collector.

Thankyou

Good morning,

Could you guys tell me what is the card to put together two TLOAD? For example to put different SPC we can use SPCADD.

5. ### Variable temperature in a BEAM

12 hours ago, Simon Križnik said:

Hi,

this is a simple analysis:

For more advanced thermal simulations please refer to FREE eBook: Learn Thermal Analysis with Altair OptiStruct

Okk thanks!!

One more question. It's a different situation. Now I have a One-Step Transient Thermal Stress Analysis (I already checked the info around this). So I did a model with the environment as heat source (the temperature of the surroundings go from 17 to 23 degrees), so I used a TLOAD, TABLED, SPC TEMP, SPCD, TSTEP and TEMP cards to do both a heat tansfer transient and a linear static analysis with the output temperatures. Now, I'd like to create more heat sources (for example due to the heating of a engine). Do I have to create the same cards now for this new source (having in mind that I want to mantain the source of the environment) and then include both TLOADS in a DLOAD? (and therefore introduce this DLOAD in the LoadStep).

Hope I explained well,

6. ### Variable temperature in a BEAM

Good afternoon,

I have a BEAM (CBEAM) component and I would like to see how it deforms due to a VARIABLE TEMPERATURE applied to the whole BEAM. Is that possible? Obviously I would only like to see how it deforms on the direction of it's axis (as a BEAM is a 1-D element). The TEMPERATURE would go from 17 to 23 degrees in 6 hours (1 degree increment every hour)

Sergio

7. ### Transient temperature analysis

Thanks! Now I changed the load step to a transient analysis because I am gonna set up an ambient temperature and with convection and conduction see how the temperature increases in the solid and also how it deforms.

Nevertheless in a tutorial about "Transient Thermal Stress Analysis" it says that I have to create a CONVECTION interface and refer it to the Material I just created.

That material is also created in the tutorial and it is a MAT1 with data for MAT 4

But when in the convection card image I try to select that material it doesn't appear

How could I fix it?

Thanks!

8. ### Transient temperature analysis

Hi!

I would like to make a transient analysis with temperature. I mean:

•  Going for example from 17 to 23 degrees of the temperature of a body in 1 hour. Making steps of 10 minutes for example (total of 6 steps).

I tried to do it with TABLED, TSTEP and creating a temperature LOAD but it doesn't work. It says :

" *** ERROR # 2094 ***
EXCITEID on TLOAD1 # 17 data references follower force or nonexistent

Could you help me?

9. ### ERROR: Starting Run Manager

1 hour ago, Simon Križnik said:

Hi,

Right click HyperMesh icon> Select Properties and change the "start in" location to another directory and try again.

Hi. I cant see where to right click the Hypermesh icon. Could you send me a picture?  Thanks!

10. ### ERROR: Starting Run Manager

Hi!

I get this error when trying to run Optistruct

"ERROR: Starting Run Manager in read-only folder. Please change "Start in" location in Properties of solvr icon/menu and/or move input file to a different location"

I've moved it to many different places and still get this error, plus I don't see where to change the "Start in" location.

11. ### Show "steps to follow" (commands)

Is it possible to create some commands or steps to follow so that when somebody else opens the file he/she can read them and know how she/he has to hide or show assemblies for a certain type of analysis or load steps? I hope I explained well. Thanks in advance!

12. ### Eigenfrequency

I made a normal modes analysis and now with Hyperview i'm trying to get the data I need. I already got the eigenvectors (X,Y,Z) for each of the modes using the Matrix Browser. Nevertheless when I get those result I don't get the natural frequency (eigenfrequency) related to that specific eigenvectors. As you see in the picture below, the frequency doesn't appear (only that those data is related to "sel1"). How could I make the eigenfrequency to appear there so ones I postprocess the results I can get access to that data?

Sergio

13. ### Shells and solid

SOLIDS in Green and SHELLS in orange

15. ### Shells and solid

Good afternoon,

I'm trying to mesh a housing and I wanna model parts of it with SHELLS and others with SOLIDS. How do I connect both?

Thanks!

16. ### Beams no moment

Good morning!

I'm trying to model the 4 cables shown in the attached file. At first I thought of using Beams to make it easier but the fact is that those cables cannot transmit moment (rotation) in the joints (2 joints in each cable). How should I do it? Do I change the element type? Is there any way of erasing restriction of the rotational DOF at the joints?

Hoping a quick response and thanks in advance!

Any news?

Thanks!

18. ### Meshing failed

Here you have it

Thanks!

19. ### Meshing failed

Hi!

I'm trying to mesh a solid with TetraMesh and it states the following error: "2 edges failed nodal setup. Meshing failed".

But I can't see anything wrong or red colored or anything that tells me where the mistake is. Even with visualisation options. The solid is created properly with bounding surfaces so I guess there are not free edges.

Could you help me?

20. ### Contact and convergence error

Good morning,

I'm running a transient analysis of 2 gears (one of them with a preload and the other one with an imposed rotation). When I run it with Optistruct I get 2 problems:

•  *** ERROR # 4965 ***
Maximum number of time increment cutbacks reached,
analysis aborted.
• The biggest problem comes here, if I analysis the results, the contact status is 0 everytime. The gears rotate but they don't seem to have a good contact. Moreover, I get high normal contact forces at points where there should be any contact (see image attached).

I also attach the .fem to make it quicker and the .out from the previous simulation

Thanks!!

21. ### Contact and convergence error

Good morning,

I'm running a transient analysis of 2 gears (one of them with a preload and the other one with an imposed rotation). When I run it with Optistruct I get 2 problems:

•  *** ERROR # 4965 ***
Maximum number of time increment cutbacks reached,
analysis aborted.
• The biggest problem comes here, if I analysis the results, the contact status is 0 everytime. The gears rotate but they don't seem to have a good contact. Moreover, I get high normal contact forces at points where there should be any contact (see image attached).

I also attach the .fem to make it quicker and the .out from the previous simulation

Thanks!!

22. ### Rotation modelling

The goal is to measure the transmission error. I already did (some months ago) a quasi-static analysis. Now I want to do it transient, dynamic so I have to change the way I apply the rotation. (In the quasi-static I did it using SPC).

23. ### Rotation modelling

Thanks! But how do I create the motion of the wheel  rotating? Would that be a transient analysis?

24. ### Rotation modelling

Hi! I wanna model the rotation of a gear (wheel) with a preload in the pinion. I asume the preload is modeled with a moment but, how do I model the rotation? And which analysis type should I choose? (I don't want  a quasi-static one). Some analysis don't let me include a LOAD. Thanks in advance!

25. ### Rotation modelling

Hi! I wanna model the rotation of a gear (wheel) with a preload in the pinion. I asume the preload is modeled with a moment but, how do I model the rotation? And which analysis type should I choose? (I don't want  a quasi-static one). Some analysis don't let me include a LOAD. Thanks in advance!

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